Bake 28 to 30 minutes, or until toothpick inserted 2 inches from side of pan comes out clean (or almost).

Immediately after removing from oven, sprinkle brownies with remaining 1 cup chocolate chips, mini marshmallows and nuts. (For a frostinglike effect, melt chocolate chips in microwave first and spread on top of brownies.) Cool completely, about 2 hours. Dip knife in hot water before slicing. Store in a tightly covered container.